Robust aluminium profile with integrated digital unit. For easy gradient/slope measurement. The measuring range is 360° divided into four 90° zones. The vials are resistant to ultraviolet light and temperature fluctuations. The vials feature a +30% magnifying glass and the horizontal vial has a luminous reflector. Easy battery replacement and automatic shut-off after 5 min. Vial tolerance in normal/upside down mode: ±0.5 mm/m. Shock-absorbing end caps with anti-glide function. The display shows 1/10 degree, percentage, mm/m or inch/ft. Tolerance of digital unit: horizontal (0°) and vertical (90°) position are ±0.05°, other angles are ±0.1°. An audible signal also indicates clearly when right angles of 0° and 90° are reached.